Daiichi Sankyo has submitted an application to Japanese regulatory authorities asking that its investigational therapy trastuzumab deruxtecan (DS-8201) be approved as a treatment for people with HER2-positive metastatic breast cancer.
The Phase 1 trial tested DS-8201 in people with different types of HER2-positive cancers, including 115 women with HER2-positive breast cancer.
Results showed that patients with metastatic breast cancer who had progressed after treatment with anti-HER2 therapies such as Kadcyla responded particularly well to the treatment. Tumors shrank at least partially in 60% of these patients, and 90% of patients achieved at least stable disease. The treatment did not cause significant side effects.
The ongoing Phase 2 DESTINY-Breast01 trial is testing DS-8201 in 253 patients with inoperable and/or metastatic HER2-positive breast cancer, recruited in over 100 sites across North America, Europe, and Asia.
The primary endpoint of the trial is objective response rate — the percentage of patients whose cancer disappears or is reduced significantly after the treatment. Secondary objectives include duration of response, progression-free survival (the time patients live without their disease worsening), and overall survival.
So far, the results of the DESTINY-Breast01 trial confirm those of the Phase 1 trial. Daiichi Sankyo plans to present the partial results at an upcoming medical meeting.
“We are proud to initiate this critical next step in the regulatory process in Japan and look forward to the presentation of the phase 2 DESTINY-Breast01 study of [fam-] trastuzumab deruxtecan to the scientific community,” Antoine Yver, MD, MSc, executive vice president and global head, oncology research and development, Daiichi Sankyo, said in a press release.
“We look forward to working closely with the Japan Health Authority on our application for [fam-] trastuzumab deruxtecan in order to bring this important potential new treatment to patients in Japan,” he said.
DS-8201 is an antibody-drug conjugate consisting of an anti-HER2 antibody (trastuzumab, brand name Herceptin) linked to the cancer-killing agent deruxtecan (a derivative of exatecan). The therapy targets cancer cells, improving specificity and reducing off-targets. It is a potential treatment for all HER2-positive types of cancer.
The treatment is being developed by AstraZeneca and Daiichi Sankyo, which have a program across North America, Europe, and Asia, including five pivotal trials. DS-8201 is an investigational treatment that has not been approved for any indication in any country.
The treatment was granted fast track designation and breakthrough therapy designation by the U.S. Food and Drug Administration for patients with advanced HER2-positive breast cancer that progressed after standard-of-care treatment.
It also received SAKIGAKE designation by the Japan Ministry of Health, Labor and Welfare for HER2-positive advanced gastric or gastroesophageal junction cancer. This designation is aimed at shortening the premarket review period in Japan.